Robotic mowers may leave uncut areas of grass that human observers can easily detect. This is because a robotic mower's path lets it bounce around the area within the boundary wire and depend on probabilities for convergence of coverage, because the robotic mower's grass length sensors are unable to efficiently find uncut grass, and because the robotic mower must return to the charging station before completely mowing a large area. There is a need for an improved robotic mower area coverage system to achieve more complete coverage and not leave uncut grass within a known or detectable boundary.